{"id":132,"date":"2008-12-09T23:52:35","date_gmt":"2008-12-09T22:52:35","guid":{"rendered":"http:\/\/www.superkikim.com\/non-classe\/gb-gb-go-et-pourquoi-diable-manque-t-il-de-la-capacite-a-mon-disque-dur\/"},"modified":"2024-08-18T01:00:24","modified_gmt":"2024-08-17T23:00:24","slug":"gb-gb-go-et-pourquoi-diable-manque-t-il-de-la-capacite-a-mon-disque-dur","status":"publish","type":"post","link":"https:\/\/akim.sissaoui.com\/en\/informatique\/gb-gb-go-et-pourquoi-diable-manque-t-il-de-la-capacite-a-mon-disque-dur\/","title":{"rendered":"GB, Gb, Go, and why on earth is there missing capacity on my hard drive?"},"content":{"rendered":"<p>=Introduction=<\/p>\n<p>Here is a big mess, or even a tangled web&#8230; What are the differences between GB, Gb, Go, Gb\/s, Gbps, and why on earth is 10% missing from my hard drive?<\/p>\n<p><!--more--><!--toc--><\/p>\n<p>=Abbreviations=<\/p>\n<p>We work every day in computing with a whole bunch of abbreviations. Here are some explanations to help you make sense of them.<\/p>\n<p>==Data Abbreviations==<\/p>\n<ul>\n<li>&#8220;b&#8221; is not equal to &#8220;B&#8221; or &#8220;o&#8221;<\/li>\n<li>b = bit. (pronounced &#8220;bit&#8221;) English word meaning &#8220;character&#8221;. Bits are &#8220;0&#8221; or &#8220;1&#8221;<\/li>\n<li>B = Byte (pronounced &#8220;bite&#8221;). English word meaning &#8220;word&#8221;. The Byte can contain 7 or 8 characters. But in the case that interests us, in modern computing, everything is based on 8.<\/li>\n<li>o = Octet: This is the French translation of Byte, nothing more, nothing less<\/li>\n<\/ul>\n<p>==Quantity Abbreviations==<\/p>\n<p>In everyday life, Kilo = thousand, Mega = 1 million, Giga = 1 billion. Easy.<\/p>\n<p>In computing, Kilo = 1,024, Mega = 1,048,576, Giga = 1,073,741,824. I&#8217;ll spare you Tera and Peta, but take Giga and multiply by 1024 for Tera, and again by 1024 for Peta.<\/p>\n<p>==&#8221;Composite&#8221; Abbreviations==<\/p>\n<p>In computing, we talk about network bandwidth in bits and capacity or transfer rate in Bytes. It&#8217;s probably historical. But I&#8217;m not a historian ([http:\/\/www.google.com Google] is your friend).<\/p>\n<p>In the world of networking, for example, ADSL or 3G, you will be sold access in Megabits per second. Mbps or Mb\/s (<span style=\"text-decoration: underline;\">M<\/span>ega <span style=\"text-decoration: underline;\">b<\/span>its <span style=\"text-decoration: underline;\">p<\/span>er <span style=\"text-decoration: underline;\">s<\/span>econd).<\/p>\n<p>When you buy a hard drive, for example, you will be sold a SATA drive with a capacity of 500GB (GigaBytes) and a transfer rate of 150MB\/s (MegaByte per second).<\/p>\n<p>=Loss of Capacity or Bandwidth=<\/p>\n<p>But the most curious among you will have noticed that when they check the capacity of their hard drive (on Windows, right-click on C: in My Computer, then &#8220;Properties&#8221;), the capacity does not match the one promised when you ordered the computer or hard drive.<\/p>\n<p>==The Truth About Hard Drives==<\/p>\n<p>The truth is that marketing teams have been at work. 1024 has become 1000 for them. But in reality, it&#8217;s the opposite. Basically, here&#8217;s the marketing calculation:<\/p>\n<ul>\n<li>1 Byte * 1000 = 1KB * 1000 = 1MB * 1000 = 1GB * 1000 = 1TB = 1&#8217;000&#8217;000&#8217;000&#8217;000 (1 trillion) Bytes<\/li>\n<\/ul>\n<p>In physical and technological reality:<\/p>\n<ul>\n<li>1&#8217;000&#8217;000&#8217;000&#8217;000 Bytes \/ 1024 = 976562500 KB = 953674.3 MB = 931.32 GB<\/li>\n<\/ul>\n<p>A &#8220;marketing&#8221; 1TB hard drive is therefore only 931GB in reality.<\/p>\n<p>==The Truth About ADSL or vDSL==<\/p>\n<p>Here too, marketing teams have had a field day, using the same trick, thus saving significant bandwidth across their vast number of customers.<\/p>\n<p>If your connection is, like mine, advertised at 5Mb\/s (Mega bits per second), it actually only runs at 5000Kb\/s and not 5120Kb\/s as one might expect.<\/p>\n<p>There may be a particular reason in the networking world for a base of 1000 instead of 1024. I haven&#8217;t looked into that level of detail.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>=Introduction= Here is a big mess, or even a tangled web&#8230; What are the differences between GB, Gb, Go, Gb\/s, Gbps, and why on earth is 10% missing from my hard drive?<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[220],"tags":[91,92,75,93],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/akim.sissaoui.com\/en\/wp-json\/wp\/v2\/posts\/132"}],"collection":[{"href":"https:\/\/akim.sissaoui.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/akim.sissaoui.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/akim.sissaoui.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/akim.sissaoui.com\/en\/wp-json\/wp\/v2\/comments?post=132"}],"version-history":[{"count":12,"href":"https:\/\/akim.sissaoui.com\/en\/wp-json\/wp\/v2\/posts\/132\/revisions"}],"predecessor-version":[{"id":2196,"href":"https:\/\/akim.sissaoui.com\/en\/wp-json\/wp\/v2\/posts\/132\/revisions\/2196"}],"wp:attachment":[{"href":"https:\/\/akim.sissaoui.com\/en\/wp-json\/wp\/v2\/media?parent=132"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/akim.sissaoui.com\/en\/wp-json\/wp\/v2\/categories?post=132"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/akim.sissaoui.com\/en\/wp-json\/wp\/v2\/tags?post=132"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}